Motor vehicles with automated gear boxes have been present on the market for a long time. Preferred use areas are motor vehicles in commercial use such as transporters and trucks. Passenger cars with sports applications or small cars have been increasingly outfitted with such transmissions in the recent past. The goal is to free the driver from shifting gears and generally to make a more comfortable and safe operation possible. Motor vehicles with such transmissions usually have two pedals as accelerator and brake. The clutch pedal can be dispensed with. A controller is available in the motor vehicle for selecting the mode of operation. Here an automatic mode, a manual shifting mode and reverse gear can be selected. If the automatic mode is selected, the gear ratio adaptation takes place automatically. Various solutions for automating the gear box exist in the commercial vehicle area. Hence there are different variants, such as, for example, pneumatic, hydraulic or purely electric systems. Which variant is selected basically depends upon the class of motor vehicles and the types of energy available in these vehicles. Furthermore, the power requirement of the actuators used is an important parameter. Pneumatic or hydraulic cylinders or electric motors which drive the selection and shifting apparatus are used as actuators depending upon the system. Actuators, which are driven by electric motors represent especially economical constructions.
There has long been a need with motor vehicle transmissions to continue to use an existing mechanical transmission that is shifted manually with an automatic, electromechanical transmission actuator. Electromechanical transmission actuators for shifting a motor vehicle transmission are known in many ways. Here a transmission is used, which is either developed together with the transmission actuator or has the adaptation elements that must be provided on the transmission for interacting with the transmission actuator.
Such a transmission actuator is known by way of example from European Patent 0 377 848 B1. There an electromechanical transmission actuator is described which has two axes of motion arranged perpendicular to each other. An individual shift finger is guided by two electric motors on the axes of motion. Moreover, the shift finger moved by the first electric motor engages with a first axis of motion into respectively an opening in the various shifter rods arranged parallel alongside one another. The shifter rod is moved by the second electric motor in its long axis by motion of the shift finger on the second axis of motion for shifting a shifting package connected respectively with a shifter rod. The mechanism of motion of the shift finger in two axes of motion arranged perpendicular toward each other indeed corresponds to the selection and shifting specification on the basis of the manual shifting diagram as well as of the selection and the displacement of the respective shifter rod, but it also requires considerable structural space on the other hand. Even the number of components required for the transmission actuator is high.
The invention is based upon the objective of diminishing the number of components and diminishing the structural space required with a transmission actuator.